Feed mechanism for machine-tools.



A. H.'SMITH.

FEED MECHANISM FOR MACHINE TOOLS.

APPLICATION FILED OUT. 25, 1912.

1,057,097. Patented Mar. 25, 1913.

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ALBERT HENRY SMITH, OF BIRMINGHAM, ENGLAND.

MECHANISM FOR MACHINE-TOOLS.

To all whom it may concern:

Be it known that I, ALBERT HENRY SMITH, subject of the King of Great Britain, residing at 155 St. Lukes road, Birmingham, in the county of Warwick, England, have invented a new and useful Feed Mechanism for Machine-Tools; and I do hereby declare the following to be a full, clear, and

exact description of the same.

My invention comprises improvements in feed mechanism for machine tools more particularly of the kind which is known as barfeed mechanism or feed collet-s as commonly employed upon capstan, and turret lathes for intermittently feeding forward a metal rod from which a large number of articles are successively machined and cut off, and refers to that class of such feed mechanism in which radially disposed gripping members are employed which grip and feed forward the rod when moving in the one direction and pass over same when moving in the other direction, the object of the present invention being to provide a gripping device which may be readily adjusted for efficient use upon rods of widely differing diameters.

According to my invention I employ a series of radially disposed members which present a chisel like point to the bar in one direction in combination with spring means for holding these radially disposed members in contact with the bar and a longitudinally moving inclined member which engages with the outer ends of the radially disposed members for positively adjusting theireffective gripping diameter.

Referring to the drawings :F igure 1 is an elevation of a feed collet according to this invention. Fig. 2 is an end view of same. Fig. 3 is a longitudinal section. Fig. 4c is a similar section with the parts adjusted to a different position. Fig. 5 illustrates the spring plunger in elevation and section. Fig. 6 illustrates the gripping finger removed.

In carrying my invention into practice as illustrated upon the accompanying drawings the mechanism is carried by a sleeve 1 bored to pass a rod of the maximum size upon which the mechanism is to operate. The forward end of this sleeve is enlarged or flanged with two inclined surfaces 2, 3. Extending from the rear inclined surfaces 2 and disposed in a radial direction but inclining toward the front end of the sleeve Specification of Letters Patent.

Application filed October 25, 1912.

Patented Mar. 25, 1913.

Serial No. 727,717.

are three or more fingers 4 having hollow chisel points 5.

In the front inclined surface 3 I drill holes corresponding with and substantially at right angles with the gripping fingers, these holes being tapped to receive spring plungers which may be in the form of a hollow screw 6 carrying a round nosed plunger 7 with a spiral spring 8 interposed between these two parts. These plungers serve to hold the inclined gripping fingers solidly against their seatings 9, but when the bar is feeding forward or when a new bar is being .inserted they allow the gripping fingers to lift, but obviously when the mechanism is feeding forward or if the bar seeks to move back the gripping fingers being already closely against their seating there will be no lost movement. The outer ends of the gripping fingers will be practically flush with the rear inclined surface aforementioned and immediately behind this surface the sleeve is screwed to receive a collar 10, the forward end of which is bored taper as 11 to substantially correspond with the rear inclined surface. This collar screwing up against the rear and outer ends of the gripping fingers which project beyond the rear inclined surface will obviously serve to force the said fingers inwardly when the ring is rotated' A second and locking ring 12 screws upon the sleeve against the rear of the adjustment ring and serves to lock same in its adjusted position. It will be obvious that when a bar as 13 is inserted between the fingers from the rear end of the mechanism the fingers may be forced outwardly to the full extent allowed by the adjustment ring, while by shifting the ring endwise a very delicate adjustment may be obtained and as the gripping fingers work under the influence of the spring plungers it will be clear that they will eificiently operate upon stock bars of slightly differing diameters without necessitating adjustment, while obviously the pressure of the spring plungers may be adjusted if so desired.

My improved feed mechanism may be employed either for holding the bar against longitudinal movement when the feed control is moving backwardly or it may be itself employed for gripping the rod for feeding forward but two of the preferred devices are preferably employed in connection with capstan or turret lathes one for each purpose.

The invention is particularly applicable for use in connection with the intermittent feed described in my United States Patent No. 10195 12 A. D. 1910 and the chucking mechanism described in United States Patent No. 9521 19 A. D. 1908.

lVhat I claim then is:-

1. In a feed collet for machine tools, the combination of a sleeve like body; a plurality of radially disposed inclined gripping fingers presenting chisel points to grip the work rod and located in said body; a corresponding mnnber of spring plungers engaging said fingers and serving to retain same in engagement with the work rod; and a longitudinally movable internally tapered adjusting member engaging the outer ends of the fingers and serving when moved longitudinally to adjust said fingers radially in order to vary the efiective gripping diameter.

2. In a feed collet for machine tools, the

combination of a sleeve like body; a plurality of radially disposed inclined gripping fingers adapted to grip the work rod and located in said body; means for retaining the fingers in engagement with the work rod; and a movable adjusting member adapted to engage the outer ends or" the fingers and simultaneously move the fingers to vary the efi'ective gripping diameters.

3a In a feed collet for machinetools, the combination of a sleeve like body having a series of radially disposed inclined openings; a plurality of similarly radially disposed inclined gripping fingers located one in each opening and presenting chisel points to grip the work rod; a corresponding number of plunger carriers screwing into said body, one being adjacent to each finger; a

' spring plunger located in each of said carriers engaging said fingers and serving to retain them in engagement with the work rod; and a longitudinally movable internally tapered adjusting member engaging the outer ends of the fingers and serving when moved longitudinally to adjust said fingers radially in order to vary the eliective gripping diameter.

4. In a feed collet for machine tools, the combination of a sleeve like body externally screwed; a plurality of radially disposed inclined gripping fingers presenting chisel points to grip the work rod and located in said body; a corresponding number of spring plungers engaging said fingers and serving to retain same in engagement with the work rod; an internally tapered ring screwing upon said body engaging the outer ends of the fingers and serving when rotated and thus moved longitudinally to adjust said fingers radially in order to vary the effective gripping diameter; and a loclc ing ring for securing the tapered ring in its adjusted position.

5. In a feed collet for machine tools, the combination of a sleeve like body; a plurality of radially disposed inclined gripping fingers presenting chisel points to grip the work rod and located in said body; means for retaining said fingers in engagement with the work rod; and a longitudinally movable internally tapered adjusting member engaging the outer ends of the fingers and serving when moved longitudinally to adjust said fingers radially in order to vary the effective gripping diameter.

6. In a feed collet for machine tools, the combination of a sleeve like body; a plurality of radially disposed gripping fingers adapted to grip the work rod and located in said body; means for retaining the fingers in engagement with the work rod; and a movable adjusting member adapted to engage the outer ends of the fingers and simultaneously move the fingers to vary the efiective gripping diameters.

In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses.

ALBERT HENRY SMITH.

Witnesses HAROLD J. C. Fonnns'rnn, NORMAN S. BARLOW.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. C. 

